This application relates generally to plastics processing, and in particular relates to sensing blend component segregation during plastics processing.
Modern plastic materials have found a wide range of markets and a variety of applications in diverse manufacturing fields. These plastic materials offer many desirable characteristics such as an excellent finish, desirable electrical, thermal and mechanical properties, low cost and a variety of colors.
Plastics are typically formed of one or more base polymers or resins, one or more colorants, and other additives. Such additives may include, for example, fiberglass for structural reinforcement, flame retardants, plasticizers, or mold release agents. The plastics are manufactured by initially mixing these components to form a substantially homogeneous polymer blend. The polymer blend then typically undergoes extrusion, or the like, to form a raw product, for example pellets. The raw products are then utilized to produce final polymer products of various forms.
During a typical finishing process, the base polymers or resins, the colorants, and other additives are fed from one or more hoppers into an extruder or the like.
During continuous feed processes, the polymer blend will fill a column connecting the hopper and the extruder. If the constituent parts of the polymer blend comprise particles of differing sizes and weights, segregation may occur in the column. The segregation of the particles, over the course of a manufacturing cycle, may be severe.
Vibrations in the system tend to cause powder constituents to migrate toward the bottom of the column, while larger constituents and pellets tend to migrate toward the top of the column. This variability within the material blend fed to the extruder will create undesirable variability in the final products.
Accordingly, it is desired to improve the process of constituent intermixing in the production of a polymer product from base resins and colorants.